This invention relates to removal of malodorous gas, such as hydrogen sulphide, from geothermal water, such as that produced from a geothermal well at the Paso Robles Inn in Paso Robles, Calif., to supply deodorized mineral water to spas located in various rooms at the Inn.
Warm mineral water from geothermal sources, such as wells and hot springs, has been used for centuries for therapeutic and recreational purposes. Mineral water often contains dissolved malodorous gases, such as hydrogen sulphide, which can be toxic, and even fatal at sufficiently high concentrations. In many public installations, the malodorous gases are simply permitted to diffuse into the atmosphere over a pool of the water available to the public. A facility of that type suffers from the disadvantages that noisome fumes are present, and public baths are less hygienic than private baths.
This invention provides apparatus and method for removing objectionable odor from geothermal water without adding anything to the water, and thus preserves the natural mineral qualities of the xe2x80x9chot springsxe2x80x9d water. Thereafter the deodorized mineral water is supplied to individual baths or spas in private rooms at a hotel, or the like.
In brief, raw geothermal well water containing a malodorous gas is passed into a partially filled storage tank to form a body of water with space above it. Water from that body is sprayed into the space above the body of water, and air pumped into the head space below the spray passes through the spray and flows from the top of the tank, carrying with it the malodorous gas. The deodorized sprayed water falls back into the body of water, and the air with malodorous gas is removed from the tank. Preferably, the water is circulated through the spray at a rate greater than the rate at which the geothermal well water enters the tank. This ensures that mineral water collected in the tank is free of any objectionable odor.
Preferably, the water passes through a filter before it is sprayed, and the air entering the tank is heated to a temperature above at the temperature of the water to minimize cooling of the sprayed water, and also promote evolution of gas from the sprayed water. The deodorized mineral water in the tank is preferably heated to the required supply temperature, usually about 107xc2x0 F., filtered, and then piped to private baths in individual rooms of a hotel or inn.
Preferably, the air passed through the sprayed water is thereafter passed through a biofilter or other suitable medium of microorganisms to remove malodorous gas from the air. In one preferred form, the air is dispersed into the soil of a flower bed where microbes in the soil decompose the hydrogen sulphide into a useful nutrient for plants.
In a further preferred form of the invention, the filter for the water is backwashed with water from time to time, and the materials removed from the filter with the wash water are used as a plant fertilizer.